Prince says he’s quitting studio recording to concentrate on theater, film and other ventures.Tuesday’s announcement comes seven months after the rock star signed a $ 100 million deal with Warner Bros. Records that made him a vice president. He will be able to continue releasing albums to satisfy that agreement because his suburban recording studio has more than 500 unreleased recordings. He has released 15 albums in 15 years. Prince’s production company said he wants to explore less conventional approaches to music and media, including interactive media and nightclubs. He completed a U.S. tour last week and has scheduled a summer European tour. And this year, New York’s Joffrey Ballet has been presenting “Billboards,” a series of dances set to Prince’s music, in various cities. Prince is also producing a reunion album for Earth, Wind & Fire and has written 10 songs for “I’ll Do Anything,” starring Nick Nolte and Tracy Ullman.